2. Patients with known somatic activating mutations of EGFR, as these patients should be offered EGFR- tyrosine kinase inhibitor (EGFR-TKI) treatment as first-line therapy. Detection of EGFR mutations and additional somatic mutations with relation to treatment will be performed centrally at the Universitätsklinikum Essen. In case immediate treatment initiation is required for medical reasons (such as superior vena cava syndrome, severely symptomatic disease) patients may be enrolled before results from EGFR testing are available. As EGFR-TKI treatment is equally effective in second-line therapy, such patients may remain on study treatment if a clinical benefit is derived.